Efficacy of ertapenem for consolidation therapy of extended-spectrum beta-lactamase-producing gram-negative infections: a case series report.

BACKGROUND: Infections caused by extended-spectrum beta-lactamase (ESBL)-producing gram-negative organisms are becoming increasingly common and present significant challenges in terms of treatment. Carbapenems is the antibiotic class of choice for treatment of these types of infections. Ertapenem is the newest carbapenem, capable of being dosed once daily, and has some in vitro but little in vivo evidence supporting its use for the treatment of these resistant infections. OBJECTIVE: To examine the clinical and microbiologic outcomes associated with ertapenem therapy of ESBL-producing Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis infections. METHODS: This was a retrospective case series that examined the clinical and microbiologic outcomes of 22 patients who received ertapenem for treatment of an ESBL infection at Rush University Medical Center in Chicago, IL, during 2003-2005. RESULTS: The majority (16/22) of patients received ertapenem for consolidation rather than initial therapy. Different antibiotics most commonly used were other carbapenems, piperacillin/tazobactam, and aminoglycosides. The most common infections treated were lower urinary tract infections and osteomyelitis. Clinical efficacy was determined in all 22 patients, with 20 (91%) patients having a positive outcome, defined as either clinical improvement or clinical cure. The best clinical cure rate was seen with wound infections, where all 3 patients examined were found to be clinically cured. Microbiologic efficacy was determined in 7 patients, with 6 (85.7%) defined as microbiologic cure. One patient was found to be both a clinical and microbiologic failure and was also found to have developed an ertapenem-resistant strain of E. coli. CONCLUSIONS: These results demonstrate potential microbiologic and clinical efficacy of ertapenem for treatment of ESBL-producing infections and the need for a prospective, randomized study examining its efficacy versus that of other carbapenems.

Faropenem medoxomil.

OBJECTIVE: To review the literature concerning the in vitro activity, pharmacokinetic properties, in vivo efficacy, and adverse events associated with a new penem antibiotic, faropenem medoxomil. DATA SOURCES: We conducted a search of MEDLINE/PubMed and International Pharmaceutical Abstracts databases for articles or abstracts using the terms faropenem, faropenem daloxate, faropenem medoxomil, SUN5555, SY5555, WY49605, RU67655, ALP201, BLA 857, and YM 044 and published through July 2007. Information on poster presentations was obtained from the drug's manufacturer. Additional articles were identified from citations in the bibliographies of review articles. Articles written in languages other than English were excluded. STUDY SELECTION AND DATA EXTRACTION: All published reports that evaluated faropenem (or its chemical synonyms) and faropenem medoxomil were used in this review. Abstracts subsequently published as full reports were excluded, and only the resulting reports were included. Abstracts without subsequently published reports were included. DATA SYNTHESIS: The in vitro activity of faropenem has been evaluated extensively against respiratory pathogens and less extensively against aerobic gram-positive, gram-negative, and anaerobic organisms. Prospective, randomized, multicenter clinical trials have demonstrated noninferiority of faropenem to comparators for the treatment of acute bacterial sinusitis, community-acquired pneumonia, acute exacerbation of chronic bronchitis, and uncomplicated skin and skin structure infections. Adverse events associated with faropenem appear to be minimal and include nausea, vomiting, and diarrhea. CONCLUSIONS: Faropenem has demonstrated excellent in vitro activity against common respiratory pathogens, many aerobic gram-positive organisms, and anaerobes. Activity against gram-negative organisms is more reserved. In vivo data suggest that faropenem is efficacious in treating community-acquired infections including uncomplicated skin and skin structure infections; however, more data may help to characterize faropenem's place in antimicrobial therapy. Replidyne, Inc., the manufacturer of faropenem, is conducting studies to address the Food and Drug Administration's concerns that resulted in a nonapprovable letter in October 2006.